The teacher’s role is to determine what explicit instruction is necessary during each of these phases based on knowledge of each student as a reader: prior knowledge of the topic; understanding of key concepts; understanding ways of thinking in the discipline; and motivation for reading and learning.
I think it is vey important for teachers to actively be thinking when planning a lesson, unit or discussion to be able to trigger that prior knowledge and use that as a base to build onto new topics/ ideas. Almost all of Science is connected in some way or another. Many people use methods of problem solving every day and don't even realize it.
we as teachers need to be able to facilitate that prior knowledge and if they do not have prior knowledge place texts to help them learn what they need to before they can read or look at another text or participate in that discussion.